Among the positions up for grabs is the backup middle infield spot, where Marwin Gonzalez appears to have a leg up on veteran Cesar Izturis. The Astros will owe Izturis $100,000 if he is not on the 40-man roster by Tuesday, but he would bring valuable experience on and off the field.

"Both of them are superior defenders," manager Bo Porter said. "Marwin has had a tremendous spring. Offensively, he's working on some things that have really increased his value from a standpoint of how he's produced offensively and the flexibility that gives our roster, being able to play multiple positions.

"Izturis is about as steady as it comes when it comes to infield defense. For a long time in Major League Baseball, his presence on and off the field is something we value. We're going to continue to evaluate that situation as well and see how it plays out."

Iztruris has been impressed by Gonzalez, who entered Saturday hitting .444.

"He's a great player, and he's been doing it all Spring Training," he said. "He's been doing his job, and hopefully it will be good for the team."

If the Astros carry eight relievers, they would have to decide between Gonzalez and Izturis. Meanwhile, Marc Krauss and Jesus Guzman could both make the club as a platoon at first base with the ability to play the outfield.

Elsewhere, Raul Valdes and Kevin Chapman are the lone lefty relievers in camp, and from among the four pitchers still battling for the final two position spots, all four could wind up in the rotation, bullpen or Minor Leagues.

"The guys that are for sure on our team, that's been communicated to them or announced they are on the team," Porter said. "Our roster is such we're not in a position we can say, 'Look, these 25 guys are on the team.' There's other variables that come into play."